Anxiolytic-like activity of Aloysia virgatavar. platyphylla leaves extract in mice / Actividad ansiolítica del extracto de hojas de Aloysia virgatavar. platyphylla en ratones

Background: Medicinal plants are part of traditional medicine and should be considered a therapeutic alternative for mental diseases. Several plants belonging to the Verbenaceae family have proved useful in treating general anxiety disorders, the most prevalent psychiatric disorders. Objective: This research aimed to verify the extract's safety, the effect on general behavior, and the effect on sleeping time, as well as to evaluate the anxiolytic-like effect of the methanol extract of Aloysia virgata var. platyphylla (Avp), in mice. Methodology: The toxicity test was done according to the OECD guide (mice groups n=5), and general behavior was observed during the assay. Sleeping time was assessed using the pentobarbital-induced hypnosis method (n=8). Male Swiss albino mice (n=6) were treated with 50 to 400 mg/kg of Avp extract and diazepam as a control. The anxiolytic-like effect was tested through the hole board and elevated plus-maze test. Results: The Avp extract has no side effects in tested doses, and no central nervous system depressant activity was noted. A. virgatavar. platyphyllaincreased exploration (number and time) in the hole board. In the elevated plus-maze, increased number and time into open arms were evidenced compared to the control group. Conclusion: With all these results, we concluded that the Avp extract is safe and has a potential anxiolytic-like activity in the animal model used

Antecedentes: Las plantas medicinales forman parte de la medicina tradicional y deben ser consideradas una alternativa terapéutica para las enfermedades mentales. Varias plantas pertenecientes a la familia Verbenaceae han demostrado su utilidad en el tratamiento de los trastornos de ansiedad, uno de los trastornos psiquiátricos más prevalentes. Objetivo: Esta investigación tuvo como objetivo verificar la seguridad del extracto, el efecto sobre el comportamiento general y el efecto sobre el tiempo de sueño, así como evaluar el efecto tipo ansiolítico del extracto metanólico de Aloysia virgata var. platyphylla(Avp), en ratones. Metodología: La prueba de toxicidad se realizó de acuerdo con la guía de la OCDE (grupos de ratones n=5), y se observó el comportamiento general durante el ensayo. El tiempo de sueño se evaluó mediante el método de hipnosis inducida por pentobarbital (n=8). Se trataron ratones albinos suizos macho (n=6) con 50 a 400 mg/kg de extracto de Avp y diazepam como control. El efecto ansiolítico se probó a través de la placa perforada y prueba del laberinto en cruz elevado. Resultados: El extracto de Avp no tiene efectos secundarios en las dosis probadas y no se observó actividad depresora del sistema nervioso central. A. virgata var. platyphylla aumentó la exploración (número y tiempo) en el tablero de agujeros. En el laberinto en cruz elevado, se evidenció un mayor número y tiempo en los brazos abiertos en comparación con el grupo de control. Conclusión: Con todos estos resultados, concluimos que el extracto de Avp es seguro y tiene una potencial actividad ansiolítica en el modelo animal utilizado

Proteína tau como biomarcador en Alzheimer preclínico / Tau protein as a biomarker in preclinical Alzheimer's disease

El desarrollo de biomarcadores de la proteína tau para el diagnóstico temprano de la enfermedad de Alzheimer (EA) emerge como un desafío fundamental, pudiendo mejorar la efectividad de un tratamiento preventivo o que enlentezca la progresión de la enfermedad. Esta revisión analiza las evidencias que justificarían el uso de la proteína tau como biomarcador en Alzheimer preclínico. Para esto se seleccionaron artículos científicos (2011-2021) que incluyeran a la proteína tau en plasma y plaquetas como biomarcador. La presencia de la proteína tau fosforilada en el líquido cefalorraquídeo presenta limitaciones por su carácter invasivo mientras que las técnicas de imagen son costosas. La medición de tau en plaquetas se correlaciona con la severidad de la demencia, y sería útil en el seguimiento de la EA. Sin embargo, la pertinencia de su uso en la detección temprana de EA se mantiene en discusión. La presencia de proteína tau fosforilada en plasma correspondería al biomarcador con mayor nivel de desarrollo, respecto de beta amiloide. La proteína tau plasmática detecta la EA con gran precisión en casos de demencia y ha sido validada por estudios neuropatológicos. p-tau217 plasmática medida por primera vez junto a técnicas de imagen, fue importante en la etapa preclínica de EA pudiendo predecir la formación de ovillos neurofibrilares. La correlación entre especies fosforiladas de tau en plasma y EA preclínica ha sido bien establecida, por lo que su uso como biomarcador podría ser de utilidad para la comprensión del proceso fisiopatológico de la neurodegeneración y la detección temprana de EA

The development of tau protein biomarkers for the early diagnosis of Alzheimer's disease (AD) emerges as a fundamental challenge, which may improve the effectiveness of preventive treatment or slow the progression of the disease. This review analyzes the evidence that would justify the use of tau protein as a biomarker in preclinical Alzheimer's disease. For this purpose, we selected scientific articles (2011-2021) that included tau protein in plasma and platelets as a biomarker. Phosphorylated tau protein in cerebrospinal fluid has limitations due to its invasiveness, while imaging techniques are expensive. The tau measurement in platelets correlates with the severity of dementia and would be helpful in the follow-up of AD. However, the relevance of its use in the early detection of AD remains under discussion. Plasma phosphorylated tau protein would correspond to the biomarker with the highest level of development for beta-amyloid. Plasma tau protein detects AD with high accuracy in cases of dementia, and neuropathological studies validate its use. Plasma p-tau217 measured for the first time with imaging techniques was important in preclinical AD and could predict the formation of neurofibrillary tangles. The correlation between plasma phosphorylated tau species and preclinical AD is well-established, so its use as a biomarker would help understand the pathophysiological process of neurodegeneration and early AD detection.

Modelos in vitro utilizados para predecir hepatotoxicidad de medicamentos en la fase pre-clínica / In vitro models used to predict hepatotoxicity of medications in the pre-clinical phase

El hígado es el órgano principal del cuerpo encargado de mantener la homeostasis interna, además cumple un rol fundamental en el metabolismo de medicamentos (xenobióticos) por lo tanto es vulnerable a lesiones fisiológicas o anatómicas. La lesión hepática inducida por fármacos (DILI) es la causa más común del fracaso del desarrollo pre-clínico y clínico de nuevos medicamentos, y de las advertencias de recuadro negro y el retiro de un medicamento del mercado. Por lo tanto, representa un problema grave para las industrias farmacéuticas, así también para el paciente, profesionales de la salud y las entidades reguladoras. Cabe mencionar que existen dos tipos de lesión hepática inducida por fármacos: farmacológicas o intrínsecas y la idiosincrásica. Durante la etapa pre-clínica del proceso de desarrollo de un medicamento se realiza un panel de cribado a los medicamentos candidatos empleando modelos celulares in vitro que incluyen sistemas de cultivos en 2D, 3D y líneas celulares de hepatoma humano, aunque también existen otros enfoques en el cual utilizan al pez cebra (reemplazo a los modelos animales) o modelos celulares basados en cribado de alto contenido. Posteriormente se emplean animales que, aunque presenten diferencias específicas respecto al humano a nivel hepatocelular igualmente se utiliza, para realizar predicciones cuantitativas y cualitativas de las principales propiedades farmacodinámicas, farmacocinéticas y toxicológicas del medicamento candidato. Actualmente existe un mayor esfuerzo para ir mejorando algunos modelos in vitro ya existentes, acoplando alguna herramienta o modificándolo genéticamente hacia el producto de interés proporcionando nuevos enfoques útiles para la predicción potencial tóxico a nivel hepático de los medicamentos candidatos.(AU)

The liver is the main organ of the body whose function is to maintain internal homeostasis, it also plays a fundamental role in the metabolism of drugs (xenobiotics), therefore it is vulnerable to physiological or anatomical injuries. Drug-induced liver injury (DILI) is the most common cause of preclinical and clinical development failure of new drugs, black box warnings, and drug recall. Therefore, it represents a serious problem for the pharmaceutical industries, as well as for the patient, health professionals and regulatory entities. It should be mentioned that there are two types of drug-induced liver injury: pharmacological or intrinsic and idiosyncratic. During the pre-clinical stage of the drug development process, candidate drugs are screened using in vitro cell models that include 2D, 3D culture systems and human hepatoma cell lines, although other approaches use zebrafish (replacement for animal models), or cell models based on high content screening. Subsequently, animals are used, which despite having specific differences with respect to humans at the hepatocellular level are also used to make quantitative and qualitative predictions of the main pharmacodynamic, pharmacokinetic and toxicological properties of the candidate drug. Currently, there is a major effort to improve some existing in vitro models, coupling a tool or genetically modifying it towards the product of interest, providing new useful approaches for the potential prediction of liver toxicity, of the candidate drugs.(AU)

Improving Dental Students Fine Motor Skills by Visualization and Mental Imagery: A Pilot Randomized Clinical Trial / Mejora de las Habilidades Motoras Finas de los Estudiantes de Odontología Mediante Visualización e Imaginería: Ensayo Clínico Aleatorizado Piloto

ABSTRACT: Clinical motor skills are essential to train dental students. There is evidence that imagery serves to acquire and improve motor skills, since imagining an action, activates the same neural areas as when this is physically performed. The aim of this pilot randomized clinical trial was to examine the feasibility of tridimensional visualization associated with mental imagery on the development of fine motor skills of dental students compared to conventional training. Seventeen dental students without previous preclinical experiences, between 18-25 years old were recruited. After giving a theoretical lecture on the inlay preparation, participants were randomly allocated in two groups. The Experimental Group (N=9) performed daily 30 minutes of "mental practice" after visualizing a video showing the execution of an ideal inlay preparation alternating it with black screen periods to facilitate the imagery. The Control Group (N= 8) performed a 30 minutes "hands on practice" daily of the same preparation. On the fifth day, both groups carried out an inlay preparation physically, which was scanned and overlapped to the virtual preparation to assess accuracy. The execution time and accuracy of the preparation performed with regard to an ideal preparation were compared between groups. The learning style and fine motor skills at baseline were similar in all participants (P>0.001). No statistically significant differences were found between the groups in terms of accuracy. The time of execution in the experimental group was significantly lower than the control group. This pilot study showed that visualization associated to mental imagery could develop fine motor skills in dental students, requiring less execution time than physical practice.

RESUMEN: Las habilidades motoras clínicas son esenciales para entrenar a los estudiantes de odontología. Existe evidencia que la imaginería sirve para adquirir y mejorar las habilidades motoras, ya que al imaginar una acción, se activan las mismas áreas neuronales que cuando la acción se realiza físicamente. El objetivo de este ensayo clínico aleatorizado piloto fue examinar la factibilidad del uso de visualización tridimensional asociada con imaginería para el desarrollo de las habilidades motoras finas en estudiantes de odontología comparado con el entrenamiento convencional. Se reclutaron diecisiete estudiantes de odontología, entre 18-25 años de edad, sin experiencias preclínicas previas. Después de recibir una clase teórica sobre la preparación de una incrustación, los participantes fueron asignados aleatoriamente a dos grupos. El grupo experimental (N = 9) realizó diariamente 30 minutos de "práctica mental" después de visualizar un video que muestra la ejecución de una preparación de incrustación ideal alternando con períodos de pantalla negra para facilitar la imaginación. El grupo de control (N = 8) realizó una práctica diaria de 30 minutos de la misma preparación. El quinto día, ambos grupos llevaron a cabo físicamente una preparación de incrustación, que fue escaneada y esta imagen se superpuso a la preparación virtual ideal para evaluar la precisión. El tiempo de ejecución y la precisión de la preparación realizada con respecto a una preparación ideal se compararon entre ambos grupos. El estilo de aprendizaje y las habilidades motoras finas al inicio del estudio fueron similares en todos los participantes (P > 0,001). No se encontraron diferencias estadísticamente significativas entre los grupos en términos de precisión. El tiempo de ejecución en el grupo experimental fue significativamente menor que en el grupo control. Este estudio piloto mostró que la visualización asociada a imaginería podría desarrollar habilidades motoras finas en estudiantes de odontología, requiriendo menos tiempo de ejecución que la práctica física.

Radiopacidade de dentes artificiais para treinamento pré-clínico de endodontia / Artificial tooth radiopacity for preclinical endodontic training

Resumo Introdução Dentes artificiais têm sido utilizados para a prática odontológica e, segundo seus fabricantes, apresentam muita similaridade aos dentes humanos para treinamento. Objetivo Avaliar a radiopacidade de dentes endodônticos artificiais para uso em atividades de ensino e saber a percepção de docentes quanto à análise radiográfica. Material e método Trinta réplicas de incisivos centrais superiores de três marcas comerciais (Fábrica de Sorrisos, IM do Brasil e Real Dent) e um incisivo humano foram utilizados. Foram dispostos sobre um sensor radiográfico o dente humano e um dente artificial de cada empresa. As análises de radiopacidade foram feitas no programa Photoshop® em triplicata em quatro regiões distintas: porção central da coroa e nos terços cervical, médio e apical do canal. A percepção quanto à utilização dos dentes como instrumento prático de ensino foi avaliada por meio de um questionário aplicado a oito professores de endodontia. Para análise estatística dos valores de radiopacidade, foi utilizada a ANOVA, seguida do teste de Tukey. Foi empregado um nível de significância de 5%. Para análise do questionário, foram empregados métodos descritivos e por porcentagem de dados no que se refere à frequência das respostas. Resultado Houve diferença de radiopacidade entre os diferentes dentes testados em cada região analisada (p > 0,05). Na percepção dos professores com relação à utilização dos dentes no ensino, eles colocaram em ordem crescente os seguintes dentes para uso: IM do Brasil, Fábrica de Sorrisos, Real Dent e humano. Conclusão A radiopacidade dos dentes artificiais foi diferente do humano. O dente artificial da Fábrica de Sorrisos apresentou os maiores valores de radiopacidade. Contudo, os professores consideraram ideais para utilização no ensino apenas o dente humano e o dente da Real Dent.

Abstract Introduction Artificial teeth have been used for dental practice which, acoording to their manufactures, bear much similarity to human teeth for training. Objective To evaluate radiopacity of artificial endodontic teeth for use in teaching activities and to know the perception of teachers regarding radiographic analysis. Material and method Thirty replicates of upper central incisors of three trade marks (Fábrica de Sorrisos, IM do Brasil and Real Dent) and a human incisor were used. On a radiographic sensor, human tooth and one artificial tooth of each marks were arranged. Radiopacity analyzes were performed using Photoshop® in triplicate in four distinct regions: central portion of the crown and in the cervical, middle and apical thirds of the canal. The perception about the use of teeth as a practical teaching instrument was evaluated through a questionnaire applied to eight teachers of Endodontics. For statistical analysis of the radiopacity values ​​ANOVA was used, followed by the Tukey test. Significance level of 5%. For the analysis of the questionnaire were used descriptive methods and percentage of data regarding the frequency of responses. Result There was a difference in radiopacity between the different teeth tested, in each region analyzed (P > 0.05). In the teachers' perception regarding the use of teeth in teaching, the teachers placed the following teeth for use: IM do Brasil, Fábrica de Sorrisos, Real Dent and human. Conclusion The radiopacity of the artificial teeth was different from the human teeth. The artificial tooth of the Fábrica de Sorrisos presented the highest values ​​of radiopacity. The teachers considered ideal for use in teaching only the human teeth and the prototype Real Dent.

Efeito de diferentes soluções irrigadoras na microdureza superficial Knoop de dentes artificiais / Effect of different irrigation solutions on the Knoop surface microhardness of artificial teeth

Resumo Introdução Dentes artificiais têm sido empregados para a prática de ensino pré-clínico. Porém, não se sabe o comportamento dos mesmos frente aos diferentes procedimentos realizados durante um tratamento endodôntico simulado. Objetivo Avaliar a microdureza de réplicas de dentes humanos, frente a diferentes soluções irrigadoras. Material e método Quarenta e cinco incisivos centrais superiores artificiais de três marcas comerciais nacionais (dentes "A", "B" e "C") e 15 incisivos humanos foram utilizados. As amostras foram seccionadas a 5 mm do ápice dentário. Os fragmentos radiculares foram fixados em resina para posterior teste de microdureza. Os ensaios da microdureza Knoop foram realizados em dois momentos: momento 1 - microdureza inicial; momento 2 - microdureza final, que foi feita após o uso das soluções irrigadoras (Cloreto de Sódio a 0,9%, Hipoclorito de Sódio a 2,5% e Gluconato de Clorexidina a 2%). As endentações deixadas na superfície da amostra foram mensuradas. O valor obtido para microdureza de cada amostra foi feita com base na média de três endentações. Para análise estatística, foram utilizados os testes ANOVA e Teste t pareado, com nível de significância de 5%. Resultado Os dentes artificiais "A" e "C" apresentaram valores inferiores de microdureza quando comparados ao dente humano (P = 0,05). Não houve diferença estatística entre os dentes artificiais "B" e o dente humano (P = 0,2428). Quanto ao uso das diferentes soluções irrigadoras, também não houve diferença na microdureza das peças dentárias. Conclusão Embora a solução irrigadora não tenha influenciado a microdureza, os dentes artificiais apresentaram valores de dureza inferiores aos do dente humano.

Abstract Introduction Artificial teeth have been used for preclinical teaching practice. However, the behavior of the same is not known in relation to the different procedures performed during a simulated endodontic treatment. Objective To evaluate the microhardness of replicates of human teeth, in front of different irrigating solutions. Material and method Forty-five artificial upper central incisors of three national trade marks (teeth "A", "B" and "C") and fifteen human incisors were used. Samples were sectioned 5 mm from the apex. The root fragments were fixed in resin for later microhardness test. The Knoop microhardness tests were performed in two moments: moment 1 - initial microhardness; moment 2 - final microhardness, which was done after the use of the irrigating solutions (0.9% sodium chloride, 2.5% sodium hypochlorite and 2% chlorhexidine gluconate). The indentations left on the sample surface were measured. The obtained value for microhardness of each sample was made based on the average of three indentations. ANOVA and Paired t-test were used for statistical analysis. Significance level of 5%. Result Artificial teeth "A" and "C" presented lower values ​​of microhardness when compared to human teeth (P = 0.05). There was no statistical difference between the artificial teeth "B" for the human (P = 0.2428). Regarding the use of different irrigation solutions, there was also no difference in the microhardness of dental pieces. Conclusion Although the irrigating solution did not influence the microhardness, the artificial teeth presented values ​​of hardness inferior to the human tooth.

Avaliação da atividade antitumoral de sais mesoiônicos no osteossarcoma: estudo in vitro / Evaluation of Mesoionic Salts antitumor activity in Osteosarcoma: In Vitro Study

O osteossarcoma é o tumor primário maligno mais comum do osso e acomete principalmente crianças e adolescentes. Cerca de 30 ­ 40% dos casos evoluem com metástases, o que diminui consideravelmente a sobrevida dos pacientes. O tratamento consiste em quimioterapia associada à cirurgia, porém, há poucas opções de medicamentos e os disponíveis provocam efeitos adversos. Além disso, determinou-se que 46,9% dos pacientes apresentam má resposta à quimioterapia pré-operatória. A identificação de novos compostos com aplicação terapêutica no osteossarcoma é fundamental para aumentar as possibilidades de tratamento dessa doença. Os sais mesoiônicos pertencem a uma classe de compostos heterocíclicos que possuem estruturas químicas que favorecem a interação com biomoléculas. A atividade antitumoral desses sais já foi verificada em diferentes tumores como hepatocarcinoma, melanoma e carcinossarcoma. Nesse contexto, o objetivo deste estudo foi avaliar o efeito antitumoral de sais mesoiônicos em células de osteossarcoma. Mediante o ensaio de redução de MTT, foi verificado que os sais MIC-F e MIC-NO2 reduziram a viabilidade relativa das células da linhagem de osteossarcoma MG-63, enquanto os sais MI-3,4-F e MI-F não foram capazes de reduzir a viabilidade das células após tratamento por 24 e 48 horas. Através da contagem das células com azul de tripan, foi verificado que o tratamento com os sais MIC-NO2 e MIC-F por 24 e 48 horas reduziu a viabilidade das células MG-63, sendo, portanto, citotóxicos. Por último, a análise de anexinaV e iodeto de propídeo por citometria de fluxo revelou que o tratamento com MIC-NO2 e MIC-F induziu morte celular por apoptose. Assim, dentre os quatro sais mesoiônicos avaliados neste estudo, apenas MIC-NO2 e MIC-F apresentaram efeitos citotóxicos em células de osteossarcoma MG-63 e, por isso, podem ser potenciais candidatos para o desenvolvimento de fármacos direcionados para o tratamento desta doença

Osteosarcoma is the most common primary bone malignancy of childhood and adolescence. About 30 - 40 % of the cases develop with metastases, which considerably decreases the survival of pacients. The current treatment includes cycles of preoperative chemotherapy followed by surgical resection and additional cycles of postoperative chemotherapy, but there are few options of chemotherapeutic agents and the available ones cause side effects. In addition, it was determined that 46.9% of patients present a poor response to preoperative chemotherapy. The identification of new compounds with promising application in osteosarcoma is relevant to the treatment of this disease. The mesoionic salts belong to a class of heterocyclic compounds with chemical structures that favor the interaction with biomolecules. The antitumor activity of these salts has already been verified in different tumors such as hepatocarcinoma, melanoma, and carcinosarcoma. The present study aimed to evaluate the antitumor effect of mesoionic salts in osteosarcoma cells. By the MTT reduction assay, it was found that the MIC-F and MIC-NO2 salts reduced the relative viability of the MG-63 osteosarcoma cells, while the MI-3,4-F and MI-F salts were not able to reduce the cell viability after treatment for 24 and 48 hours. By counting cells with trypan blue, it was found that treatment with the MIC-NO2 and MIC-F salts, for 24 and 48 hours, reduced the viability of MG-63 cells and were therefore cytotoxic. Finally, the analysis of annexin-V and propidium iodide by flow cytometry revealed that the treatment with MICNO2 and MIC-F induced cell death by apoptosis. Thus, among the four mesoionic salts evaluated in this study, only MIC-NO2 and MIC-F had cytotoxic effects on MG-63 osteosarcoma cells and, therefore, may be potential candidates for the development of drugs targeted to the treatment of this disease

Estudio preclínico del efecto de las esencias florales de Bach en la inflamación aguda / Preclinical effect of the Bach flower essence in acute inflammation

Introducción: los estudios preclínicos que de forma habitual preceden al uso de un medicamento convencional pudieran convertirse en la solución a la comprobación de las acciones terapéuticas de medicinas naturales como las flores de Bach. La inflamación aguda y los modelos experimentales que la simulan son herramientas útiles en este camino. Objetivo: evaluar la actividad antiinflamatoria de las esencias florales de Bach en un modelo de inflamación aguda en ratas. Métodos: se realizó un estudio preclínico experimental piloto controlado y aleatorizado a ciegas en la UTEX de la Universidad de Ciencias Médicas de Villa Clara en el mes de Diciembre del 2010. El modelo experimental consistió en la inducción de edema plantar con dextrán. Se conformaron en 5 grupos de 6 animales (en total 30 ratas). Se trataron con las esencias Beech, Vervain y Rescue Remedy, respectivamente; mientras que los 2 restantes fueron control (negativo con placebo y positivo con Difenhidramina). Resultados: se observaron diferentes efectos en los tratamientos utilizados. Beech y Vervain mostraron propiedades antiinflamatorias con diferencias significativas al placebo, cuestión que avala su utilización en el tratamiento de patologías donde la inflamación es un denominador común. Estas acciones fueron selectivas ya que Beech tuvo efecto inmediato y Vervain mostró actividad sobre la inflamación en tercera hora. Otro preparado, el Rescue Remedy, no mostró esta actividad diferente al placebo

Background: the preclinical studies that in their habitual form precede the use of a conventional drug, could become a solution to testing therapeutic actions of natural medications such as the Bach flowers. The acute inflammation and the experimental models that simulate it are very useful tools in this direction. Objective: to evaluate the antinflammatory activity of the Bach flower essence in an acute inflammation model in rats. Methods: a pilot experimental preclinical study, controlled and blindly randomized, was carried out at the UTEX of the Medical Sciences University of Villa Clara on December 2010. The experimental model consisted on the induction of plantar oedema with Dextran. 5 groups of 6 animals were formed (30 rats in total). They were treated with Beech and Vervain essences and Rescue Remedy respectively; while the remaining 2 formed the control group (negative with placebo and positive with Diphenhydramine). Results: different effects in the treatments were observed. Beech and Vervain showed antinflammatory properties with significant differences form placebo, condition that endorse their use in the treatment of pathologies where inflammation is a common factor. These actions were selective because Beech had an immediate effect and Vervain showed its activity on the inflammation in the third hour. Other preparation, the Rescue Remedy, showed that its activity was not different from placebo

Estudio del desempeño preclínico y clínico de una amalgama dental comercial / Preclinical and clinical evaluation of a commercial dental amalgam

Introducción: la amalgama de plata es un material restaurador para uso en dientes posteriores. El propósito de este estudio fue observar las características de trabajo de la amalgama dental Nu Alloy dp® en dientes de ivorina y, posteriormente, evaluar algunas cualidades clínicas de este material restaurador, dieciocho meses después de ser colocado en boca. Métodos: se realizaron 153 restauraciones de amalgama dental Nu Alloy dp® en dientes de ivorina en el laboratorio y se registró la percepción de los odontólogos. Posteriormente se realizaron 306 obturaciones en pacientes para evaluar el comportamiento clínico del material restaurador. Resultados: en el estudio de laboratorio se reportó una evaluación buena de los odontólogos para las variables condensación, tallado, bruñido y pulido con porcentajes de respuesta favorables entre el 68 y 86%. En el estudio clínico se revisaron 92 obturaciones al final del estudio, dieciocho meses de seguimiento, con los siguientes resultados: evaluación excelente para las variables desgaste oclusal, falla cohesiva y evaluación radiográfica; buena valoración para las variables de integridad marginal, textura superficial y decoloración. Conclusiones: de la fase de laboratorio se puede decir que la amalgama dental Nu Alloy dp® presentó buena valoración de sus características de manipulación, las cuales se reflejan posteriormente en los resultados obtenidos en la evaluación clínica. Con los resultados encontrados en la revisión clínica a dieciocho meses se concluye que el comportamiento clínico de la amalgama fue excelente.

Introduction: silver amalgam is a dental material which is used in restorative clinical dentistry for posterior teeth. The purpose of this study was to evaluate the preclinical performance of the Nu Alloy dp® dental amalgam in plastic teeth, and, then to evaluate the clinical performance of the restorative material after eighteen months of being placed in the mouth. Methods: 153 NuAlloy dp® dental amalgam restorations were made in the preclinical phase and the dentists’ perception was recorded. Subsequently 306 restorations were made in patients in order to evaluate the clinical performance of the restorative material. Results: a good evaluation was reported by the dentists in the preclinical study regarding the following variables: cohesion, carving, burnishing and polishing, with favorable answer percentages between 68% and 86%. Ninety two restorations were examined at the end of the clinical study with following results: excellent evaluation for oclusal wear, cohesive failure of the material, and radiographic evaluation variables; and good evaluation for marginal integrity, surface texture and discoloration variables. Conclusions: good performance results were obtained with Nu Alloy dp® dental amalgam in the preclinical phase which are reflected subsequently in the clinical evaluation results. The results found in the evaluation at eighteen months allowed us to conclude that the clinical performance was excellent. Dental amalgam requires maintenance appointments in order to carry out its polishing every six months and to keep its surface texture and brightness which were obtained in the first appointments.

Diagnóstico pré-clínico da doença de Alzheimer: prevenção ou vaticínio? / Preclinical diagnosis of Alzheimer disease: prevention or prediction?

The diagnosis of Alzheimers disease (AD) for cases with dementia may be too late to allow effective treatment. Criteria for diagnosis of preclinical AD suggested by the Alzheimers Association include the use of molecular and structural biomarkers. Preclinical diagnosis will enable testing of new drugs and forms of treatment toward achieving successful preventive treatment. But what are the advantages for the individual? To know that someone who is cognitively normal is probably going to develop ADs dementia when there is no effective preventive treatment is definitely not good news. A research method whereby volunteers are assigned to receive treatment or placebo without knowing whether they are in the control or at-risk arm of a trial would overcome this potential problem. If these new criteria are used wisely they may represent a relevant milestone in the search for a definitive treatment for AD.

O diagnóstico da doença de Alzheimer (DA) quando já existe demência pode ser tarde demais para permitir um tratamento eficaz. Critérios para o diagnóstico pré-clínico da AD sugeridos pela Associação de Alzheimer incluem o uso de biomarcadores moleculares e estruturais. O diagnóstico pré-clínico possibilitará avaliar novos medicamentos e formas de tratamento para alcançar o sucesso do tratamento preventivo. Mas quais são as vantagens do diagnóstico pré-clínico para o indivíduo? Receber a informação de que provavelmente irá se manifestar a demência da DA quando não existe um método eficaz de prevenção não é definitivamente uma boa notícia. Um método de pesquisa onde os voluntários sejam incluídos para receber tratamento ou placebo, sem saber se estão no grupo controle ou no grupo de risco, pode ser uma maneira de resolver este problema. Se esses novos critérios forem utilizados com sabedoria serão um marco relevante na busca do tratamento definitivo da DA.

Importância dos estudos pré-clínicos em animais de experimentação para a cardiologia intervencionista: [revisão] / The importance of pre-clinical animal testing in interventional cardiology: [review]

O tratamento da doença cardiovascular mudou radicalmente nas últimas duas décadas, proporcionando aos pacientes uma sobrevida maior e melhor qualidade de vida. Grande parte desse sucesso deve-se à introdução de novas terapias. Em nenhuma outra área essa mudança foi mais evidente do que na cardiologia intervencionista, pois nos últimos vinte anos as intervenções cardiovasculares percutâneas saíram do terreno experimental para formar a base terapêutica dos portadores de doença cardiovascular sintomática. O desenvolvimento dessas tecnologias, desde os primeiros estágios, requer a realização de estudos pré-clínicos com modelos animais. É possível compreender os mecanismos terapêuticos desses dispositivos, uma vez introduzidos na esfera clínica, comparando-se os achados das pesquisas realizadas com modelos animais com amostras de exames anatomopatológicos. Esta análise apresenta uma visão geral do papel emergente dos estudos pré-clínicos, bem como dos resultados, do desenvolvimento e da avaliação de modelos amimais, nas tecnologias de intervenção cardiovascular percutânea para tratamento de pacientes com doença cardiovascular sintomática.

The treatment of cardiovascular disease has changed dramatically over the past 2 decades, allowing patients to live longer and better quality lives. The introduction of new therapies has contributed much to this success. Nowhere has this been more evident than in interventional cardiology, where percutaneous cardiovascular intervention has evolved in the past 2 decades from a quirky experimental procedure to a therapeutic cornerstone for patients with symptomatic cardiovascular disease. The development of these technologies from the earliest stages requires preclinical experiments using animal models. Once introduced into the clinical arena, an understanding of therapeutic mechanisms of these devices can be ascertained through comparisons of animal model research findings with clinical pathological specimens. This review provides an overview of the emerging role, results of preclinical studies and development, and evaluation of animal models for percutaneous cardiovascular intervention technologies for patients with symptomatic cardiovascular disease.